This invention relates to a connection device for detachably connecting an associated unit such as a camera to an eyepiece section of an endoscope.
Recently, a method has been adopted which allows observation of body cavities through, for example, a camera connected to an eyepiece section of an endoscope. Usually the camera is connected to the eyepiece section through a connection device. British Patent No. 2,053,506 and West German Utility Model No. 6,926,837 disclose this type of known connection device. This connection device has an annular member to which the eyepiece section of an endoscope is connected and in which a plurality of balls are arranged along its inner surface. The balls are depressed by a locking ring on the outer periphery of the annular member, causing them to be projected into the annular member. As a result, the balls are brought into engagement with the eyepiece section, whereby the eyepiece section is locked onto the annular member.
The balls are disposed in holes formed in the wall of the annular member. In order to retain the balls in the holes, each hole has a diameter smaller than that of the balls. For this reason, the balls can be projected through the holes into the annular member only to an extent corresponding to less than one half the size of the balls, the diameter of the balls in relation to the diameter of the holes being the limiting factor. Thus, the connection device finds restricted application with particular endoscopes. It cannot be applied to an endoscope of a type whose eyepiece section differs somewhat in diameter or in the inclination of its taper section, yet many kinds of endoscopes are known whose eyepiece sections differ in size. For obvious reasons it is not economical to have to use a different connection device on each and every occassion according to the particular size of a given eyepiece section of an endoscope.